Four channel stereophonic broadcasting system and receiving device

ABSTRACT

A four channel broadcasting system of the instant invention utilizes an FM broadcasting wave of the pilot tone system having a main channel domain containing a first composite signal, a first sub-channel domain containing a second composite signal, and a second sub-channel domain containing a third and fourth composite signals. One embodiment is disclosed in which the first, second, third, and fourth composite signals take the form 2LF+2RF+LB+RB, LF-RF+2LB-2RB,2LF-2LB,2RF-2RB, respectively. A second embodiment is disclosed in which the first, second, third, and fourth composite signals take the form LF+RF-LB&lt;135*+RB&lt;+45*,LF-RF+LB&lt;-45*+RB&lt;-45*,LF+RF+LB&lt;+45*+RB&lt; -135*,LFRF+LB&lt;+135*+RB&lt;+135* respectively. Various matrixing arrangements for formulating four discrete output signals LF,RF,LB,RB from the four composite signals are also disclosed.

United States Patent [191 Cho i 1 FOUR CHANNEL STEREOPIIONICBROADCASTING SYSTEM AND RECEIVING DEVICE [75] Inventor: Mayumi Cho,Tokyo, Japan [73] Assignee: Pioneer Electronic Corporation, Tokyo, Japan22 Filed: May 29,1973

21 Appl. No.: 364,476

[30] Foreign Application Priority Data June 6, 1972 Japan 4766391 [52]US. Cl. .1 179/15 HT [51] Int. Cl. H0411 5/00 {58] Field of Search....179/15 ET, 1 GO, 100.4 ST, 179/1001 TD, 1 G

[56] References Cited UNITED STATES PATENTS 3,708,623 1/1973 Dorren179/15 BT 3,745,252 7/1973 Bauer i 179/1 GQ 3,761,628 9/1973 Bauer 179/1GQ OTHER PUBLICATIONS Why the Four Channel War Need Not Take Place byJuly 22, 1975 Feldman Audio Magazine July 1972.

Primary Examiner-Kathleen H. Claffy Assistant Examiner-Thomas DAmicoAttorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57]ABSTRACT A four channel broadcasting system of the instant inventionutilizes an FM broadcasting wave of the pilot tone system having a mainchannel domain containing a first composite signal, a first sub-channeldomain containing a second composite signal, and a second sub-channeldomain containing a third and fourth composite signals. One embodimentis disclosed in which the first, second, third, and fourth compositesignals take the form 2LF+2RF+LB+RB, LFRF+2- LB2RB,2LF-2LB,2RF-2RB,respectively. A second embodiment is disclosed in which the first,second, third, and fourth composite signals take the form LF- +RFLB135+RB +45,LFRF+LB 45+R- B 45,LF+RF+LB +45+R- B l35,LFRF+LB +l35+RB +135respectively. Various matrixing arrangements for formulating fourdiscrete output signals LF,RF,LB,RB from the four composite signals arealso disclosed.

8 Claims, 12 Drawing Figures PATENTEIJJULQZ ms ':=.896, 269

HGI

SHEET PATENTEDJULPZ I915 91 KHZ FOUR CHANNEL STEREOPI-IONIC BROADCASTINGSYSTEM AND RECEIVING DEVICE BACKGROUND OF THE INVENTION This inventionrelates to PM stereophonic broadcasting and, more particularly, to afour-channel stereophonic broadcasting system utilizing an FM radio waveas a transmission medium and a receiver set adapted therefor.

As well known in the art, various known four-channel stereophonic soundtransmission systems generally are divided into two classes: one beingcalled a discrete system in which four-route sound signals areindependently recorded or broadcasted and regenerated, and the otherbeing called a matrix system in which fourroute signals are combined byan encoder into two channel components and thereafter the two combinedsound signals are regenerated by supplying them to a matrix devicewhereby reproduced sounds may have characters like those possessed whenraw sounds were picked up to thereby provide for the effect that soundsare properly oriented and for the feeling of presence.

The discrete system four channel FM stereophonic broadcasting systemthat employs main channel, first sub-channel, and second sub-channeldomains is currently experimentally in operation by one broadcastingstation in the U.S.A. (called the Dorren system), and it appears certainthat the above discrete system fourchannel stereophonic broadcastingwill spread hereafter. On the other hand, the matrix system offourchannel stereophonic broadcasting now in practice, transmits foursound signals of the four-channel stereophonic information after theyare encoded into the form of two composite signals by means of the mainchannel and first sub-channel domains. Further, radio receiver sets arecurrently manufactured and sold that include a decoder and fouramplifiers to receive the matrix system four-channel stereophonic radiowave and regenerate the four-channel stereophonic sounds.

In view of the foregoing background of the presentday stereophonicbroadcasting, it would be convenient and important to perfect a novelfour-channel stereophonic broadcasting method whereby the broadcastsignal is compatible with monaural and two-channel stereophonicreceivers currently employed, but can be decoded by use of theaforementioned receiver including a decoder into the form of the matrixsystem fourchannel stereophonic sounds, and, if a second subchanneldomain is added thereto in the future, can be decoded into discretesystem four-channel stereophonic sounds.

Therefore, it is an object of the present invention to provide a novelstereophonic broadcasting method and a receiver set adapted toregenerate the sound signals from the radio wave as broadcasted inaccordance with the instant novel broadcasting method.

It is a specific object of the present invention to provide a novelfour-channel stereophonic broadcasting method which is adapted tobroadcast by use of a single radio wave medium any one of monaural,two-channel stereo. matrix system four-channel stereo, and discretesystem fourchannel stereo information and gives compatibility andnatural feeling to a bearer even when a user selects any type of thepresent-day known radio receivers or demodulating means.

It is another object of the present invention to provide a receiver setwhich is adapted to receive and demodulate the sound signals asbroadcasted in accordance with the instant broadcasting method.

It is still another object of the present invention to provide anadapter to be used in conjunction with the conventional matrix systemfour-channel stereophonic receiver.

SUMMARY OF THE INVENTION According to the present invention, there isprovided a novel four-channel stereophonic broadcasting method whichutilizes an FM broadcasting wave of the pilot tone system that utilizesa main channel domain and a first sub-channel domain, as well known inthe art. The present stereophonic broadcasting method providesadditionally a second sub-channel domain to permit transmission andregeneration of the matrix system four-channel stereophonic informationas well as the discrete system four-channel stereophonic inform ation.

In the broadcasted wave, the main channel domain carries all signals ofthe four-channel stereophonic information. The first sub-channel domaincarries signal components from which two composite signals can bederived by combining the signal components with the signals included inthe main channel domains. The two composite signals may be produced byencoding the four signals of the matrix system four-channel stereophonicinformation. The second sub-channel domain carries signal componentsfrom which the signals of the discrete system four-channel stereophonicinformation can be derived by combining the signal components with thesignals of the main channel domain and the first sub-channel domain.

For demodulation of the four-channel stereophonic wave broadcasted inaccordance with the present broadcasting method and regeneration of thefour channel stereophonic sound signals, the present invention providesfurther a discrete system four-channel stereophonic receiver set and adiscrete system fourchannel stereophonic adapter to be used inconjunction with a conventional stereophonic receiver of the matrixsystem four-channel type. The instant receiver has variety in internalstructure as will become clear as description proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1, 4, 7 and 10 are frequencyspectrum diagrams of multiplex signals employable in the presentinvention;

FIGS. 2, 5, 8 and 11 are vector diagrams of signal componentsfrequency-modulated in the domains of main channel, first sub-channeland second subchannel, corresponding to the frequency spectrum diagramsof FIGS. 1, 4, 7 and 10, respectively;

FIGS. 3, 6, 9 and 12 are explanatory schematic diagrams showing decodermatrix sections of receivers according to the present invention,corresponding to FIGS. 2, 5, 8 and 11, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the fourindividual embodiments it should be noted that the broadcast signalformats of FIGS. I, 4, 7 and I0 in combination with the vectorrelationships shown in FIGS. 2, S, 8 and I I provide sufficientinformation to enable anyone of ordinary skill in the art to generatethe described signals.

Referring first to FIGS. 1 through 3 showing a first embodiment of thepresent invention, FIG. 1 is a frequency spectrum diagram of a multiplexsignal employable in the present invention. In the drawing, a firstsignal MI is employed directly as a main channel component, a secondsignal S1 is converted to a carrier suppressed AM double-sideband signalwith the center fre quency of 38 KHz and employed as a first sub-channelcomponent, and third and fourth signals S2 and S3 are converted throughquadrature modulation to a carrier suppressed AM double-sideband signalwith the center frequency of such as 76 KHz and employed as a secondsub-channel component. The three above channel components are togetherfrequency modulated onto a carrier in the VHF band. The I) KI-lz signalshown in the drawing is a so-called pilot carrier. The signal groupconsisting of signals M1 and SI and the pilot carrier corresponds to thesignal arrangement according to the so-called pilot tone system whichprovides the standard FM broadcasting radio wave now widely employedthroughout the world.

FIG. 2 is a vector diagram of signal components Ml, S1, S2 and S3 shownin FIG. I. It will be understood that. if the composite signal shown inFIG. I is received and regenerated by a monaural receiver, only thesignal M l is extracted and, because the signal MI includes all signalcomponents which are to be oriented on leftfront (L right-front (Rleft-back (L and rightback (R sides, respectively, as appreciated fromthe vector diagram. music can be enjoyed by use of the monaural receiverwithout an artificial feeling. Further, in the case where the signal isreceived by a conventional FM stereo receiver, signals S4 and S5 can bederived from the signals M1 and S1 through a matrix device MTl includinga phase inverter Pl of a receiver. as shown in FIG. 3. Because thesignals S4 and S5 include chiefly signal components which are to beoriented on left and right sides, respectively, they can be employeddirectly as two-channel sound signals.

The matrices operate in an apparent manner in view of the drawings.Matrix MTI will be explained in detail. The other matrices operate inthe same manner. MTl has two inputs and two outputs. The first andsecond inputs receive the M1 and SI signals, respectively. The firstoutput is the vector sum of M1 and S1. As shown at S4, the vector sumresults in cancellation of R and reinforcement of L The second output isthe vector sum of M1 and SI inverted. As shown at SS, the vector sumresults in cancellation of L,- and reinforcement of R The two abovesignal components (S4 and S5) correspond to composite signals producedby encoding four signals into two, and this feature of signal encodingprocess is called a CBS or SO system developed by Columbia BroadcastingSystem Incorp.. U.S.A.

Then, if the above signals S4 and S5 are supplied without modificationto loudspeakers positioned on left-front and right-front sides toregenerate corresponding sounds, and the signals M1 and SI are alsosupplied to a matrix device MT2 including 45 and +45 phase shifters anda phase inverter Pl to derive signals 56 and S7 which are in turnsupplied to loudspeakers positioned on left-back and right-back sides toregenerate corresponding sounds, the matrix system four-channelstereophonic sound field can be produced.

Signals S2 and S3 shown in vector representation in FIG. 2 are obtainedby demodulating the second subchannel signal component as broadcasted.As shown schematically in FIG. 3, signals S8 and S9 are obtained byapplying the signal M] of the main channel and one signal S2 included inthe second sub-channel to a matrix device MT3 including a phase inverterPl. Signals S10 and 811 are obtained through matrix operation byapplying the signal S1 of the first sub-channel and the other signal S3included in the second sub-channel to a matrix device MT4 including aphase inverter PI. Further, the signals S8 and S10 are processed by amatrix device MTS including a phase inverter PI to obtain signals S12and S13, and the signals S9 and 811 are processed by a matrix device MT6including 45 and +45 phase shifters and a phase inverter PI to obtainsignals S14 and S15. As shown in vector representation in FIG. 3, thesignals S12 through S15 have no crosstalk therebetween but the samephase relationship, so that by applying these signals to correspondingloudspeakers positioned on left-front, right-front, left-back andright-back sides around a hearer, the discrete system four-channelstereophonic sound field can be pro duced.

In the first embodiment of FIGS. 1 through 3, pre-consideration is givenin designing the decoder so that the structures of matrix devices MT5and MT6 correspond to those of matrix devices MTI and MT2, respectively,which serve to generate the signals S4 through S7 of the matrix systemfour-channel stereophonic information. Therefore, in case a userpossesses a decoder or receiver of the matrix system type, it ispossible to regenerate the discrete system four-channel stereophonicsound output by attaching a circuit device capable of processing thesecond sub-channel component to obtain the signals S8 through S1 1, asan adapter to the conventional receiver, while operating simultaneouslythe matrix devices MT] and MT2 originally included in the receiver, thisbeing one of the advantages of the present invention.

FIGS. 4 through 6 show a second embodiment of the present inventionwherein, while the same modulated signal as that of the first embodimentis employed, the combination of matrix devices to form the decoderdiffers from the arrangement of matrix devices of the first embodiment.That is, the signals M1 and S1 shown in FIG. 5 are applied to the matrixdevice MTI including the phase inverter Pl to obtain the signals S4 andS5 which can be directly employed as the two channel stereophonic soundsignals, as described in connection with the first embodiment.

Different from the first embodiment. the signals S4 and S5 of the secondembodiment are applied to a matrix device MT7 including phase shiftersto obtain signals S7 and S6. and the latter signal S6 is then applied toa phase inverter PI to obtain the signal S6.

Thus, it will be understood that, even by use of two matrix devices MTIand MT7 and one phase inverter Pl, as is the case of the secondembodiment, all the signals ofthe matrix system four-channelstereophonic information can be obtained. similar to the firstembodiment.

The right hand half of the circuit shown in FIG. 6 is for obtaining thediscrete system four-channel stereophonic sounds by use of the secondsub-channel signal component. That is, signals S16 and S17 are obtainedby applying the signals S2 and S3 to a matrix device MTS for matrixprocessing. Here, it should be noted that if a carrier signal to beadded in demodulating the second sub-channel component is phase shifteda 45, the signals S16 and S17 can be obtained directly as demodulationsignals, thus, the above provision obviates the use of the matrix deviceMTS.

In FIG. 6, the signals S4 and S16 are applied to a matrix device MT9including a phase inverter F1 for matrixing to produce signals S18 andS19 and, then, the signals S5 and S17 are applied to a matrix device MTincluding a phase inverter Pl for matrixing to produce signals S20 andS21. Thereafter, the signals S19 and S21 are applied to a matrix deviceMTll including a 90 phase shifters for matrixing to produce signals S22and S23, and the latter S23 is processed by a phase inverter Pl toproduce a signal S23.

By supplying the thus obtained signals S18, S20, S22 and S23 toloudspeakers positioned on left-front, rightfront, right-back andleft-back sides, respectively, around the hearer, the discrete systemfour-channel stereophonic sounds can be regenerated and heard.

FIGS. 7 through 9 show a third embodiment of the present inventionutilizing the same frequency spectrum feature as that employed in theforegoing embodiments. As shown schematically in FIGS. 7 and 8, a signalM2 is a composite monaural signal including four signals with a weightput upon front signal components, thus, by regenerating this compositesignal, a natural monaural sound can be heard. This main signal M2 and asignal S24 in the first sub-channel are processed by the matrix deviceMT] included in the conventional receiver to produce signals S27 andS28. The obtained signals S27 and S28 have signal components whosemajority portions are to be oriented on left and right sides,respectively, thus, by use of these two signals without modification thetwo-channel stereophonic sounds can be heard. Here, it will be notedthat the two above signal components correspond to two composite signalsproduced by encoding four channel signals; this latter feature wasproposed by Peter Scheiber, U.S.A., and is called the Scheiber system.Accordingly, by use of a matrix device MT12, including attenuators eachwith the attenuation coefficient of0.4l4 and phase inverters Pl, foursignals 829 through S32 can be derived from the signals S27 and S28.

As will be understood from H6. 9, the four signals S29 through S32permit hearing of substantially properly oriented four-channelstereophonic sounds as they are applied to loudspeakers, while a littlecrosstalk effect will remain in the view point of the matrix systemfour-channel stereophonic information.

Signals S and S26 included in the second subchannel in an FM mode are,after demodulation, applied to a matrix device MT13, including phaseinverters Pl, through respective attenuators each with the attentuationcoefficient of 0.828, shown in rectangular block X828? The matrix deviceMTl3 receiving also the signals S29 through S32 generates signals S33through $36. The resulting signals S33 through S36 are in turn processedby a matrix device MTl4 including X.414 attenuators and phase invertersP1 to obtain four independent sound signals S37 through S40.

FIGSv 10 through 12 show a fourth embodiment of the present inventionwhich is designed so that the discrete system four-channel stereophonicsignals are directly obtained, contrary to the above third embodimentwhere the matrix system four-channel signals are additionally produced.The main channel signal M2 and the first sub-channel signal S24 arematrixprocessed by the matrix device MTl to obtain the signals S27 andS28 as is the case of the third embodiment; however, in this fourthembodiment, the signals S25 and S26 obtained from the second sub-channelare combined at a matrix device MT15 together with the signals S27 andS28 to generate signals S41 through S44. Because these signals S41through S44 include a little crosstalk component each, the signals S25and S26 after being phase inverted are added at a next matrix deviceMT16 in order to cancel the crosstalk components.

Though specific embodiments of the present invention have been describedhereinabove, it should be understood that the broadcasting method andreceiver set of the present invention are not to be limited only to thespecific features described hereinabove and illustrated in the drawings.For example, the set of various signal components that are to befrequency modulated through the main channel, first sub-channel andsecond sub-channel domains should not be limited to those sets whichhave the foregoing specific vector relationships, The requirements whichare to be satisfied in the pres ent invention are that: the main channeldomain includes at least four signal components of the four channelroutes; the first sub-channel domain includes signal components fromwhich two composite signals that may be produced by encoding foursignals of the matrix system four-channel stereophonic information canbe derived through combining them with the signals included in the mainchannel domain; and the second sub-channel domain includes signalcomponents from which the discrete system four-channel stereophonic'sound signals can be derived through combining them with the signalsincluded in the main channel and first sub-channel domains. Therefore,so far as the above requirements are fulfilled, various signalcomponents in various relative modes can be selected freely as the mainchannel, first sub-channel and second subchannel signal components.

Further, though all the demodulating means were constructed by matrixcircuits in the illustrated embodiments, they can also be realized byuse of switching (time-dividing) means as is the case of the pilot tonesystem stereophonic receiver.

What is claimed is:

1. A discrete system four-channel stereophonic receiver adapted toreceive a four-channel stereophonic frequency modulated wave of thefollowing format:

a main channel domain having all four signals of fourchannelstereophonic information in said main channel domain, said four signalsbeing designated as R Ly, R and L and comprising a first compositesignal in said main channel domain such that the vector representationsof said four signals of said first composite signal are of equalmagnitudes and have the following angular displacements from thepositive x-axis in two-dimensional space:

R Lp 0 R,, +45 L 35 a first sub-channel domain having all four signalsof four-channel stereophonic information in said first sub-channeldomain, said four signals comprising a second composite signal in saidfirst sub-channel domain such that the vector representations of saidfour signals of said second composite signal are of equal magnitudes andhave the following angular displacements from the positive x-axis intwodimensional space:

a second sub-channel domain having all four signals of four-channelstereophonic information in said second sub-channel domain, said foursignals comprising third and fourth composite signals in said secondsub-channel domain such that the vector representations composite signalare of equal magnitudes and have the following angular displacementsfrom the positive x-axis in two-dimensional space:

and the vector representations of said four signals of said fourthcomposite signal are of equal magnitudes and have the following angulardisplacements from the positive x-axis in two-dimensional space:

said discrete system four-channel stereophonic receiver comprising:

first means for matrix-processing said first and third composite signalsto generate a fifth composite signal consisting of the signalsdesignated R and L and a sixth composite signal consisting of thesignals designated R and L second means for matrix-processing saidsecond and fourth composite signals to generate a seventh compositesignal consisting of the signals designated R and Lp and an eighthcomposite signal consisting of the signals designated R and L andcombining means for receiving said fifth, sixth, seventh and eighthcomposite signals and deriving therefrom four independent sound signalsR,-, L,-, R;;, and L.

2. A discrete system four-channel stereophonic receiver as recited inclaim 1 wherein said combining means comprises:

third means for matrix-processing said fifth and seventh compositesignals to generate said independent sound signals designated R and Land fourth means for matrix-processing said sixth and eighth compositesignals to generate said independent sound signals designated R and L 3.A discrete system four-channel stereophonic receiver adapted to receivea four-channel stereophonic frequency modulated wave of the followingformat:

a main channel domain having all four signals offourchannel stereophonicinformation in said main channel domain, said four signals beingdesignated as R,-, L,-, R and L and comprising a first com pos' itesignal in said main channel domain such that the vector representationsof said four signals of said first composite signal are of equalmagnitudes and have the following angular displacements from thepositive x-axis in two-dimensional space:

a first sub-channel domain having all four signals of four-channelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal are of equal magnitudes and have the followingangular displacements from the positive x-axis in twodimensional space:

a second sub-channel domain having all four signals of four-channelstereophonic information in said second sub-channel domain, said foursignals comprising third and fourth composite signals in said secondsub-channel domain such that the vector representations of said foursignals of said third composite signal are of equal magnitudes and havethe following angular displacements from the positive x-axis intwo-dimensional space:

and the vector representations of said four signals of said fourthcomposite signal are of equal magnitudes and have the following angulardisplacements from the positive x axis in two-dimensional space:

said discrete system four-channel stereophonic receiver comprising:

first means for matrix-processing said first and second compositesignals to generate a fifth composite signal consisting of the signalsdesignated Ly, R

and L and a sixth composite signal consisting of the signals designatedR R and L second means for matrix-processing said third and fourthcomposite to generate a seventh composite signal consisting of thesignals designated L R and L and an eighth composite signal consistingof the signals designated R,-, R and L and combining means for receivingsaid fifth, sixth, seventh and eighth composite signals and derivingtherefrom four independent sound signals R L R and L 4. A discretesystem four-channel stereophonic receiver as recited in claim 3 whereinsaid combining means comprises:

third means for matrix-processing said fifth and seventh compositesignals to generate one of said independent sound signals designated Land a ninth composite signal consisting of the signals designated R andL fourth means for matrix-processing said sixth and eighth compositesignals to generate one of said independent sound signals designated Rand a tenth composite signal consisting of the signals designated R andL and fifth means for matrix-processing said ninth and tenth compositesignals to generate said independent sound signals designated R and L 5.A discrete system four-channel stereophonic receiver adapted to receivea four-channel stereophonic frequency modulated wave of the followingformat:

a main channel domain having all four signals of fourchannelstereophonic information in said main channel domain, said four signalsbeing designated a R,-, L,-, R,, and L and comprising a first compositesignal in said main channel domain such that the vector representationsof said four signals of said first composite signal have the followingrelative magnitudes and angular displacements from the positive x-axisin two-dimensional space:

a first sub-channel domain having all four signals of four-channelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal have the following relative magnitudes andangular displacements from the positive x-axis in twodimensional space:

a second sub-channel domain having all four signals of four-channelstereophonic information in said second sub-channel domain, said foursignals comprising third and fourth composite signals in said secondsub-channel domain such that the vector representations of said signalscomprising said third composite signal have the following relativemagnitudes and angular displacements from the positive x-axis intwo-dimensional space:

and the vector representations of said signals comprising said fourthcomposite signal have the following relative magnitudes and angulardisplacements from the positive x-axis in two dimensional space:

said discrete system four-channel stereophonic receiver comprising:

means for matrix-processing said first and second composite signals togenerate a fifth composite signal and a sixth composite signal eachcomprising all four signals of four-channel stereophonic information,

means for decoding said fifth and sixth composite signals into seventh,eighth, ninth and tenth composite signals each consisting of a differentcombination of three of said four signals of four-channel stereophonicinformation, and

means for combining said third and fourth composite signals with saidseventh, eighth, ninth and tenth composite signals to derive therefromfour independent sound signals R L R and L 6. A discrete systenfour-channel stereophonic receiver adapted to receive a four-channelstereophonic frequency modulated wave of the following format:

a main channel domain having all four signals of fourchannelstereophonic information in said main channel domain, said four signalsbeing designated as R Ly, R and L and comprising a first compositesignal in said main channel domain such that the vector representationsof said four signals of said first composite signal have the followingrelative magnitudes and angular displacements from the positive x-axisin two-dimensional space:

a first sub-channel domain having all four signals of four-channelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal have the following relative magnitudes andangular displacements from the positive x-axis in twodimensional space:

a second sub-channel domain having all four signals of four-channelstereophonic information in said second sub-channel domain, said foursignals comprising third and fourth composite signals in said secondsub-channel domain such that the vector representations of said signalscomprising said third composite signal have the following relativemagnitudes and angular displacements from the positive x-axis intwo-dimensional space:

and the vector representations of said signals comprising said fourthcomposite signal have the following relative magnitudes and angulardisplacements from the positive x-axis in two-dimensional space:

said discrete system four-channel stereophonic receiver comprising:

first means for matrix-processing said first and second compositesignals to generate a fifth composite signal and a sixth compositesignal each comprising all four signals of four-channel stereophonicinformation,

second means for matrix-processing said third,

fourth, fifth and sixth composite signals to generate seventh, eighth,ninth and tenth composite signals each consisting of a differentcombination of three of said four signals of four-channel stereophonicinformation, and

means for decoding said seventh, eighth, ninth and tenth compositesignals to derive therefrom four independent sound signals R L R and L7. In a frequency modulated broadcasting system for discretefour-channel stereophonic information, the method of broadcasting saidfour-channel information comprising:

generating a pilot signal,

modulating a main channel carrier with all four signals of four-channelstereophonic information in said main channel domain, said four signalsbeing designated as R L R and L and comprising a first composite signalin said main channel domain such that the vector representations of saidfour signals of said first composite signal are of equal magnitudes andhave the following angular displacements from the positive x-axis intwodimensional space:

modulating a first sub-channel suppressed carrier having a frequencyequal to a first multiple of said pilot signal with all four signals offour-channel stereophonic information in said first sub-channel domain,said four signals comprising a second composite signal in said firstsub-channel domain such that the vector representations of said foursignals of said second composite signal are of equal magni tudes andhave the following angular displacements from the positive x-axis intwo-dimensional space:

quadrature modulating a second sub-channel suppressed carrier having afrequency equal to a second multiple of said pilot signal with all foursignals of four-channel stereophonic information in said secondsub-channel domain, said four signals comprising third and fourthcomposite signals in said second sub-channel domain such that the vectorrepresentations of said four signals of said third composite signal areof equal magnitudes and have the following angular displacements fromthe positive x-axis in two-dimensional space:

and the vector representations of said four signals of said fourthcomposite signal are of equal magnitudes and have the following angulardisplacements from the positive x-axis in two-dimensional space:

modulating a first sub-channel suppressed carrier having a frequencyequal to a first multiple of said pilot signal with all four signals offour-channel stereophonic information in said first sub-channel domain,said four signals comprising a second composite signal in said firstsub-channel domain such that the vector representations of said foursignals of said second composite signal have the following relativemagnitudes and angular displacements from the positive x-axis intwo-dimensional space:

14 tudes and angular displacements from the positive x-axis intwo-dimensional space:

and the vector representations of said signals comprising said fourthcomposite signal have the following relative magnitudes and angulardisplacements from the positive x'axis in two-dimensional space:

1. A discrete system four-channel stereophonic receiver adapted toreceive a four-channel stereophonic frequency modulated wave of thefollowing format: a main channel domain having all four signals offour-channel stereophonic information in said main channel domain, saidfour signals being designated as RF, LF, RB and LB and comprising afirst composite signal in said main channel domain such that the vectorrepresentations of said four signals of said first composite signal areof equal magnitudes and have the following angular displacements fromthe positive x-axis in twodimensional space: RF<0*LF<0*RB<+45*LB<-135* afirst sub-channel domain having all four signals of fourchannelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal are of equal magnitudes and have the followingangular displacements from the positive x-axis in two-dimensional space:RF<180*LF<0*RB<-45*LB<-45* a second sub-channel domain having all foursignals of fourchannel stereophonic information in said secondsub-channel domain, said four signals comprising third and fourthcomposite signals in said second sub-channel domain such that the vectorrepresentations composite signal are of equal magnitudes and have thefollowing angular displacements from the positive xaxis intwo-dimensional space: RF<0*LF<0*RB<-135*LB<+45* and the vectorrepresentations of said four signals of said fourth composite signal areof equal magnitudes and have the following angular displacements fromthe positive x-axis in twodimensional space:RF<180*LF<0*RB<+135*LB<+135* said discrete system four-channelstereophonic receiver comprising: first means for matrix-processing saidfirst and third composite signals to generate a fifth composite signalconsisting of the signals designated RF and LF and a sixth compositesignal consisting of the signals designated RB and LB, second means formatrix-processing said second and fourth composite signals to generate aseventh composite signal consisting of the signals designated RF and LFand an eighth composite signal consisting of the signals designated RBand LB, and combining means for receiving said fifth, sixth, seventh andeighth cOmposite signals and deriving therefrom four independent soundsignals RF, LF, RB, and LB.
 2. A discrete system four-channelstereophonic receiver as recited in claim 1 wherein said combining meanscomprises: third means for matrix-processing said fifth and seventhcomposite signals to generate said independent sound signals designatedRF and LF, and fourth means for matrix-processing said sixth and eighthcomposite signals to generate said independent sound signals designatedRB and LB.
 3. A discrete system four-channel stereophonic receiveradapted to receive a four-channel stereophonic frequency modulated waveof the following format: a main channel domain having all four signalsof four-channel stereophonic information in said main channel domain,said four signals being designated as RF, LF, RB and LB and comprising afirst composite signal in said main channel domain such that the vectorrepresentations of said four signals of said first composite signal areof equal magnitudes and have the following angular displacements fromthe positive x-axis in two-dimensional space: RF<0*LF<0*RB<+45*LB<-135*a first sub-channel domain having all four signals of four-channelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal are of equal magnitudes and have the followingangular displacements from the positive x-axis in two-dimensional space:RF<180*LF<0*RB<-45*LB<-45* a second sub-channel domain having all foursignals of four-channel stereophonic information in said secondsub-channel domain, said four signals comprising third and fourthcomposite signals in said second sub-channel domain such that the vectorrepresentations of said four signals of said third composite signal areof equal magnitudes and have the following angular displacements fromthe positive x-axis in two-dimensional space: RF<0*LF<0*RB<-135*LB<+45*and the vector representations of said four signals of said fourthcomposite signal are of equal magnitudes and have the following angulardisplacements from the positive x-axis in two-dimensional space:RF<180*LF<0*RB<+135*LB<+135* said discrete system four-channelstereophonic receiver comprising: first means for matrix-processing saidfirst and second composite signals to generate a fifth composite signalconsisting of the signals designated LF, RB and LB and a sixth compositesignal consisting of the signals designated RF, RB and LB, second meansfor matrix-processing said third and fourth composite to generate aseventh composite signal consisting of the signals designated LF, RB andLB and an eighth composite signal consisting of the signals designatedRF, RB and LB, and combining means for receiving said fifth, sixth,seventh and eighth composite signals and deriving therefrom fourindependent sound signals RF, LF, Rb, and LB.
 4. A discrete systemfour-channel stereophonic receiver as recited in claim 3 wherein saidcombining means comprises: third means for matrix-processing said fifthand seventh composite signals to generate one of said independent soundsignals designated LF and a ninth composite signal consisting of thesignals designated RB and LB, fourth means for matrix-processing saidsixth and eighth composite signals to generate one of said inDependentsound signals designated RF and a tenth composite signal consisting ofthe signals designated RB and LB, and fifth means for matrix-processingsaid ninth and tenth composite signals to generate said independentsound signals designated RB and LB.
 5. A discrete system four-channelstereophonic receiver adapted to receive a four-channel stereophonicfrequency modulated wave of the following format: a main channel domainhaving all four signals of four-channel stereophonic information in saidmain channel domain, said four signals being designated a RF, LF, RB andLB and comprising a first composite signal in said main channel domainsuch that the vector representations of said four signals of said firstcomposite signal have the following relative magnitudes and angulardisplacements from the positive x-axis in two-dimensional space: 2RF<0*2 LF<0*1 RB<0*1 LB<0* a first sub-channel domain having all foursignals of four-channel stereophonic information in said firstsub-channel domain, said four signals comprising a second compositesignal in said first sub-channel domain such that the vectorrepresentations of said four signals of said second composite signalhave the following relative magnitudes and angular displacements fromthe positive x-axis in two-dimensional space: 1 RF<180*1 LF<0*2 RB<180*2LB<0* a second sub-channel domain having all four signals offour-channel stereophonic information in said second sub-channel domain,said four signals comprising third and fourth composite signals in saidsecond sub-channel domain such that the vector representations of saidsignals comprising said third composite signal have the followingrelative magnitudes and angular displacements from the positive x-axisin two-dimensional space: 2 LF<0*2 LB<180* and the vectorrepresentations of said signals comprising said fourth composite signalhave the following relative magnitudes and angular displacements fromthe positive x-axis in two dimensional space: 2 RF<0*2 RB<180* saiddiscrete system four-channel stereophonic receiver comprising: means formatrix-processing said first and second composite signals to generate afifth composite signal and a sixth composite signal each comprising allfour signals of four-channel stereophonic information, means fordecoding said fifth and sixth composite signals into seventh, eighth,ninth and tenth composite signals each consisting of a differentcombination of three of said four signals of four-channel stereophonicinformation, and means for combining said third and fourth compositesignals with said seventh, eighth, ninth and tenth composite signals toderive therefrom four independent sound signals RF, LFRB, and LB.
 6. Adiscrete systen four-channel stereophonic receiver adapted to receive afour-channel stereophonic frequency modulated wave of the followingformat: a main channel domain having all four signals of four-channelstereophonic information in said main channel domain, said four signalsbeing designated as RF, LF, RB and LB and comprising a first compositesignal in said main channel domain such that the vector representationsof said four signals of said first composite signal have the followingrelative magnitudes and angular displacements from the positive x-axisin two-dimensional space: 2 RF<0*2 LF<0*1 RB<0*1 LB<0* a firstsub-channel domain having all four signals of four-channel stereophonicinformation in said first sub-channel domain, said four siGnalscomprising a second composite signal in said first sub-channel domainsuch that the vector representations of said four signals of said secondcomposite signal have the following relative magnitudes and angulardisplacements from the positive x-axis in two-dimensional space: 1RF<180*1 LF<0*2 RB<180*2 LB<0* a second sub-channel domain having allfour signals of four-channel stereophonic information in said secondsub-channel domain, said four signals comprising third and fourthcomposite signals in said second sub-channel domain such that the vectorrepresentations of said signals comprising said third composite signalhave the following relative magnitudes and angular displacements fromthe positive x-axis in two-dimensional space: 2 LF<0*2 LB<180* and thevector representations of said signals comprising said fourth compositesignal have the following relative magnitudes and angular displacementsfrom the positive x-axis in two-dimensional space: 2 RF<0*2 RB<180* saiddiscrete system four-channel stereophonic receiver comprising: firstmeans for matrix-processing said first and second composite signals togenerate a fifth composite signal and a sixth composite signal eachcomprising all four signals of four-channel stereophonic information,second means for matrix-processing said third, fourth, fifth and sixthcomposite signals to generate seventh, eighth, ninth and tenth compositesignals each consisting of a different combination of three of said foursignals of four-channel stereophonic information, and means for decodingsaid seventh, eighth, ninth and tenth composite signals to derivetherefrom four independent sound signals RF, LF, RB, and LB.
 7. In afrequency modulated broadcasting system for discrete four-channelstereophonic information, the method of broadcasting said four-channelinformation comprising: generating a pilot signal, modulating a mainchannel carrier with all four signals of four-channel stereophonicinformation in said main channel domain, said four signals beingdesignated as RF, LF, RB and LB and comprising a first composite signalin said main channel domain such that the vector representations of saidfour signals of said first composite signal are of equal magnitudes andhave the following angular displacements from the positive x-axis intwo-dimensional space: RF<0*LF<0*RB<+45*LB<-135* modulating a firstsub-channel suppressed carrier having a frequency equal to a firstmultiple of said pilot signal with all four signals of four-channelstereophonic information in said first sub-channel domain, said foursignals comprising a second composite signal in said first sub-channeldomain such that the vector representations of said four signals of saidsecond composite signal are of equal magnitudes and have the followingangular displacements from the positive x-axis in two-dimensional space:RF<180*LF<0*RB<-45*LB<-45* quadrature modulating a second sub-channelsuppressed carrier having a frequency equal to a second multiple of saidpilot signal with all four signals of four-channel stereophonicinformation in said second sub-channel domain, said four signalscomprising third and fourth composite signals in said second sub-channeldomain such that the vector representations of said four signals of saidthird composite signal are of equal magnitudes and have the followingangular displacements from the positive x-axis in two-dimensional space:RF<0*LF<0*RB<-135*LB<+45* and the vector representations of said foursiGnals of said fourth composite signal are of equal magnitudes and havethe following angular displacements from the positive x-axis intwo-dimensional space: RF<180*LF<0*RB<+135*LB<+135*
 8. In a frequencymodulated broadcasting system for discrete four-channel stereophonicinformation the method of broadcasting said four channel informationcomprising: generating a pilot signal, modulating a main channel carrierwith all four signals of four-channel stereophonic information in saidmain channel domain, said four signals being designated as RF, LF, RBand LB and comprising a first composite signal in said main channeldomain such that the vector representations of said four signals of saidfirst composite signal have the following relative magnitudes andangular displacements from the positive x-axis in two-dimensional space:2 RF<0*2 LF<0*1 RB<0*1 LB<0* modulating a first sub-channel suppressedcarrier having a frequency equal to a first multiple of said pilotsignal with all four signals of four-channel stereophonic information insaid first sub-channel domain, said four signals comprising a secondcomposite signal in said first sub-channel domain such that the vectorrepresentations of said four signals of said second composite signalhave the following relative magnitudes and angular displacements fromthe positive x-axis in two-dimensional space: 1 RF<180*1 LF<0*2 RB<180*2LB<0* quadrature modulating a second sub-channel suppressed carrierhaving a frequency equal to a second multiple of said pilot signal withall four signals of four-channel stereophonic information in said secondsub-channel domain, and four signals comprising third and fourthcomposite signals in said second sub-channel domain such that the vectorrepresentations of said signals comprising said third composite signalhave the following relative magnitudes and angular displacements fromthe positive x-axis in two-dimensional space: 2 LF<0*2 LB<180* and thevector representations of said signals comprising said fourth compositesignal have the following relative magnitudes and angular displacementsfrom the positive x-axis in two-dimensional space: 2 RF<0*2 RB<180*.